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Rare exoplanet 37 EP

Kepler-139 e

RA 282.3919° · Dec 43.8894° · exoplanet

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Score breakdown

· 5 badges
37 pts · Rare
Rare 50 pts → Epic
  • Richly packed system +14
  • Orbits a Sun-like star +8
  • Distant (over 1,000 light-years) +6
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 37

13 more points to reach Epic.

Badges

  • Confirmed exoplanet · +5
  • Distant (over 1,000 light-years) · +6
  • Gas giant · +4
  • Richly packed system · +14
  • Orbits a Sun-like star · +8

Trivia

Hard to believe

  • It would float. It is less dense than water. Drop it in a big enough ocean and the whole world would bob on the surface.

What it actually is

  • What it is made of. Lighter than Neptune — a puffed-up ball of hydrogen and helium with no surface anywhere on it to stand on.
  • Crowded system. One of at least 5 planets orbiting its star.

Sense of scale

  • In perspective. Far away by human standards, yet still a local address inside the Milky Way's spiral arms.

Find it in the sky

  • How to spot it. At magnitude 12.8 it is far too faint for the eye: this one belongs to cameras and long exposures.
  • Northern sky. It rides the northern half of the sky — an easier target the further north you are.
  • Best time of year. It stands highest in the middle of the night around July — that's when to go looking.

Could we get there?

  • Verdict. Impossible with our current technology — and the next millennium of it.

Properties

density gcc
0.808
diameter km
174759.94
discovery facility
W. M. Keck Observatory
discovery method
Radial Velocity
discovery year
2023
dist ly
1275.3939
eccentricity
0.0131
eq temp k
154.06
host star teff
5622
insolation
0.0991
mag
12.775
mass earth
378
name
Kepler-139 e
orbital period days
2047.6354
radius earth
13.7
semi major au
3.2358
sys num planets
5
sys num stars
1

About Kepler-139 e

Kepler-139 e is a rare exoplanet. It lies about 1,275.4 light-years from Earth, shines at apparent magnitude 12.78, has an equilibrium temperature near 154 K and spans roughly 13.7 Earth radii.

Lighter than Neptune — a puffed-up ball of hydrogen and helium with no surface anywhere on it to stand on.

How to see it

At apparent magnitude 12.78, it takes a larger telescope or a long-exposure image to capture.

Like any astronomical target, Kepler-139 e is best seen from a dark site away from city lights, and when it is above the horizon depends on your latitude and the time of year. The visibility panel above works out tonight's viewing window for your saved location.

Why Kepler-139 e is a rare exoplanet

Kepler-139 e scores 37 points on Spacedle's rarity scale, which places it in the rare tier. Another 13 points would lift it into a rarer tier.

That score comes from 5 science badges — Confirmed exoplanet, Distant (over 1,000 light-years), Gas giant, Richly packed system and Orbits a Sun-like star — each earned for a real, measurable property of the object. Rarity on Spacedle is never random: the more remarkable an object's astrophysics, the more badges it collects, the higher it scores, and the rarer it ranks.